/*=========================================================================*\
* Unix domain socket
* LuaSocket toolkit
\*=========================================================================*/
#include "lua.h"
#include "lauxlib.h"

#include "unixstream.h"
#include "unixdgram.h"

/*-------------------------------------------------------------------------*\
* Modules and functions
\*-------------------------------------------------------------------------*/
static const luaL_Reg mod[] = {
    {"stream", unixstream_open},
    {"dgram", unixdgram_open},
    {NULL, NULL},
};

static void add_alias(lua_State* L, int index, const char* name, const char* target) {
  lua_getfield(L, index, target);
  lua_setfield(L, index, name);
}

static int compat_socket_unix_call(lua_State* L) {
  /* Look up socket.unix.stream in the socket.unix table (which is the first
   * argument). */
  lua_getfield(L, 1, "stream");

  /* Replace the stack entry for the socket.unix table with the
   * socket.unix.stream function. */
  lua_replace(L, 1);

  /* Call socket.unix.stream, passing along any arguments. */
  int n = lua_gettop(L);
  lua_call(L, n - 1, LUA_MULTRET);

  /* Pass along the return values from socket.unix.stream. */
  n = lua_gettop(L);
  return n;
}

/*-------------------------------------------------------------------------*\
* Initializes module
\*-------------------------------------------------------------------------*/
UNIX_API int luaopen_socket_unix(lua_State* L) {
  int i;
  lua_newtable(L);
  int socket_unix_table = lua_gettop(L);

  for (i = 0; mod[i].name; i++)
    mod[i].func(L);

  /* Add backwards compatibility aliases "tcp" and "udp" for the "stream" and
   * "dgram" functions. */
  add_alias(L, socket_unix_table, "tcp", "stream");
  add_alias(L, socket_unix_table, "udp", "dgram");

  /* Add a backwards compatibility function and a metatable setup to call it
   * for the old socket.unix() interface. */
  lua_pushcfunction(L, compat_socket_unix_call);
  lua_setfield(L, socket_unix_table, "__call");
  lua_pushvalue(L, socket_unix_table);
  lua_setmetatable(L, socket_unix_table);

  return 1;
}

UNIX_API int luaopen_libluasocket_unix(lua_State* L) {
  return luaopen_socket_unix(L);
}
